Post on 08-Jul-2015
Will Jenkins
Intelligent Electronic Systems
Human and Systems Engineering
Department of Electrical and Computer Engineering
Real-Time Vehicle Performance Monitoring
With Data Integrity
INTELLIGENT TRANSPORTATION SYSTEMS:
Page 1 of 33Real-Time Vehicle Performance Monitoring With Data Integrity
Abstract
Goal of the thesis:
• Development of a vehicle position and
performance tracking system (VPPTS)
• Design of buffering techniques to provide
data integrity for real-time monitoring
applications
• Detailed analysis of the performance of these
techniques in enhancing data integrity
Problem Statement:
Limited bandwidth availability and weak signal
quality of wireless networks present problems
that can hinder data integrity for any real-time
monitoring system.
Hypothesis:
A novel data buffering technique would
improve the integrity of the data transmission
while using a wireless network that can be
prone to interference and poor signal strength.
Data cache
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Introduction
Cornerstone of next generation intelligent transportation systems (ITS):
• seamless integration of in-vehicle networking with existing wireless telephony
infrastructure;
• remote access to on-board diagnostics and performance data.
Design is based on:
• popular standards for wireless communications — GSM/GPRS and
CDMA2000/EvDO;
• in-vehicle standards for diagnostic information, OBD-II, J1708, J1939, is used
to gather performance data;
• GPS technology to provide vehicle location;
• Web development tools to provide Internet access via a vehicle tracking web
site.
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Intelligent Transportation Systems (ITS)
• Uses networks of collaborative vehicles to optimize
traffic flow and provide dynamic routing capability
(―intelligent network‖)
• Relies heavily on vehicle
communication systems
including peer-to-peer and
peer-to-base station
communications
NETWOR
K
• Incorporates seamless
integration of in-vehicle
networking with existing
wireless telephony
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System Overview
Wireless
Network
Web /
Database
Server
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Vehicle Networks: OBD-II/J1939/J1708
OBD-II Protocol Signal Type(s)
SAE J1850 VPW Variable Pulse Width Modulation at 10.4k Baud
SAE J1850 PWM Pulse Width Modulation at 41.7k Baud
ISO 9141-2
Two Serial Lines at 10.4k Baud:
Half-duplex (L)
Full-duplex (K)
ISO 15765 (CAN) Single or Dual Wire Serial Lines up to 500 Kbps
Heavy-Duty Protocol Signal Type(s)
SAE J1708 Modified RS-485 network at 9.6k Baud
SAE J1939 CAN-based at 250 Kbps
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GSM/GPRS and CDMA2000/EvDO Network
• Digitally encodes voice signals using the GSM
06.10 compressor models at 13kbps
• General Packet Radio Service (GPRS) – data
communication layer over a GSM wireless transmission
link (171.2 Kbps)
• Global System for Mobile
Communication (GSM) - the fastest
growing mobile communication
standard based on TDMA
Internet
Wireless
Network
• Packet format allows for full compatibility with existing Internet services
• Code Division Multiple Access (CDMA) 2000 – theoretically
allows for greater capacity than GSM (144 Kbps)
• Evolution Data Only (1xEV-DO) – enhances CDMA2000 with high data
rate capabilities by time division multiplexing the downlink allowing up
to 3.1 Mbps downlink and 1.8 Mbps uplink
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Similar Proposed Systems
• Many proposed systems exploit the above technologies
and enhancements to provide a wireless-based location
tracking system
• Incorporate enhancements to
increase the accuracy of GPS such
as Differential GPS (DGPS) and also
wide area augmentation system
(WAAS)
• Exploit the wireless communication
network to assist GPS
• The VPPTS incorporates GPS and vehicle performance
data and permits real-time tracking and post analysis of
this data
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Generation 1: Proof of Concept Prototype
• Sony Ericsson GC-82 EDGE
PC card
• Garmin GPS 35-PC
• Laptop with two COM ports
(RS232) and a 16-bit
compatible PCMCIA port
• BR-3 OBD-II Interface
• Operates on OBD-II
protocols specified in
SAE J1850
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Generation 2: Campus Bus Network Pilot
• A PC104 embedded solution was
developed.
• The shuttles operate on the
heavy-duty protocols J1708
and J1939.
• Windows XP Embedded
operating system
• Geographical Information System (GIS)
providing faster map rendering based
on GPS coordinates.
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Generation 2: Embedded Pilot System Components
• Sony Ericsson GC-83
EDGE/GPRS PC card• Garmin GPS 35-PC
• Kontron MOPSlcd7 PC-104+ CPU
board
• Dearborn DPAIII/PC104
Interface
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Generation 3: Integrated Single Board Computer
• A single board computer system
that can operate in tight spaces in
a vehicle (i.e. behind dash or
under seat)
• Integrated I/O and communication
modules (GPS, vehicle interface,
and wireless device)
• Embedded Linux OS
• Uses less resources than Windows
XP Embedded, which reduces the
requirements for the hardware
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Generation 3: Embedded Pilot System
• Kyocera KPC650 1xEV-DO
PC card
• Micro/sys SBC4495
• Elmscan 5
• Autotap HDV100A
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Initial Web/Database Server
Table Contents
Stops Label and GPS coordinates
Routes Label and list of topology in-order of traversal
Buses Current location
• Separate database for real-time and stored data are
maintained
• Apache web server
• Tomcat extensions
• Five http servlets to maintain
data flow from the vehicle to the
database to the user interface.
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Web Interface with GIS Database Backend
Issues with initial web and database server:
• Map size (>1 MB only for campus)
• Resources used by applet
Solutions:
• Geographical Information System (GIS) mapping
system generate images on-the-fly (Google Maps,
Microsoft Local Live)
• Creating a JavaScript-based interactive website
based on AJAX
• GIS allows for information relative to GPS
coordinates to be displayed providing a more
interactive experience.
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Buses
ID Bus ID Route ID Latitude Longitude
1 898 Maroon 33.4539 88.7942
2 903 Maroon 33.4589 88.7984
3 1003 Express 33.4549 88.7945
Gauges
ID Bus ID speed RPM TPS EngineLoad FuelEconomy CoolantTemp
1 898 12 1456 25 35 8 88
2 903 14 1543 14 15 10 89
3 1003 2 945 0 7 13 86
Vehicle Database Enhancement
Protocol
Protocol Name Param IDParam
Name
Param
Index
Param
TranslationParm Units
J1708 54 speed X 0.5 mph
J1939 0CF00400 rpm 3 0.125 rpm
• Store RAW data stringData String Example
vehicleID|date|time|latitude|longitude|1st parameter=protocol;ID,index,value|
2ndparameter=protocol;ID,index,value|3rdparameter=protocol;ID,index,value|…
vehicleId=2|date=240706|utc=115052|gpsN=33.467185|gpsW=-88.795952|data1=J1850;010D,0;4D|
data2=J1850;010C,0;17E4|data3=J1850;0111,0;19|data4=J1850;0104,0;17|data5=J1850;0105,0;88
• Provide a protocol table for translation
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Initialize
Vehicle Interface
Device
Send Current
GPS and PID
Data
Set
Communication
Protocol
Retrieve
GPS
Data
Poll
Vehicle
Data
Decode
NMEA
Sentence
Initial Vehicle Communicator Process
• The vehicle interface device
must be initialized.
• The GPS data is gathered.
• NMEA GPRMC sentence
contains UTC data, longitude,
and latitude.
• Send data via wireless communication network
• The communication protocol is
set based on vehicle protocol.
• Specified vehicle data is polled
What if the connection
becomes degraded?
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• This technique increases
the reliability of the system
by making sure the data is
transmitted to the server
Data Collection Process: Data Buffering Techniques
• Adding a data cache allows
the transmission of stored
data along with new data
• Initial buffering technique stored timed-out data to a file
and transmitted at the end of the day
What if the transmission takes
longer than the data
resolution (e.g. 1 second)?
• Data integrity was not ensured with this approach
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Multi-Threaded Approach: Enhancing Data Buffering
• Data integrity was not ensured with a single-threaded
application as data might not be gathered during timeout
• A multi-threaded approach was developed
• Each thread handles
communication to a
specific interface
(vehicle, GPS, network)
• Semaphores are used to
synchronize the data
between the threads
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Experiment Scenario: Generation 2 Experiment 1
• Single-threaded application with data-caching buffering
technique
• Monitor 2 buses over a single day of operation
• Wireless conditions: Good
• Data resolution: 1 second
• Bus 1205
• J1939 vehicle network
• CDMA2000/1xEV-DO wireless network
• Bus 903
• J1708 vehicle network
• GSM/GPRS wireless network
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Experiment Scenario: Generation 2 Experiment 1
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Experiment Scenario: Generation 2 Experiment 1
Shuttle Bus 903 1205
Network GSM/GPRS CDMA2000/EVDO
Total Data Strings Available 52200 50791
Total Data Strings Gathered 42345 50087
Transmission Attempts of
Gathered Data Strings42345 50087
Timeouts During Transmission 1383 229
Gathered Data Strings
Successfully Transmitted42345 50087
Percent Gathered Data Strings
Buffered2.65% 0.44%
Percent Buffered Data Strings
Successfully Transmitted100% 100%
Percent Data Strings Not
Gathered18.88% 1.39%
Average Successful
Transmission Time (seconds)0.767 0.365
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Experiment Scenario: Generation 2 Experiment 2
• Single-threaded application with data-caching buffering
technique
• Monitor 2 buses over a single day of operation
• Wireless conditions: Poor
• Data resolution: 1 second
• Bus 1205
• J1939 vehicle network
• CDMA2000/1xEV-DO wireless network
• Bus 903
• J1708 vehicle network
• GSM/GPRS wireless network
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Experiment Scenario: Generation 2 Experiment 2
Focus on this
hour
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Experiment Scenario: Generation 2 Experiment 2
During this time data
gathering has halted
while reconnecting
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Experiment Scenario: Generation 2 Experiment 2
Shuttle Bus 903 1205
Network GSM/GPRS CDMA2000/EVDO
Total Data Strings Available 161 30647
Total Data Strings Gathered 140 4969
Transmission Attempts of Gathered Data
Strings140 4696
Timeouts During Transmission 11 1068
Gathered Data Strings Successfully
Transmitted140 4065
Percent Gathered Data Strings Buffered 6.83% 3.48%
Percent Buffered Data Strings
Successfully Transmitted100% 86.56%
Percent Data Strings Not Gathered 13.04% 84.68%
Average Successful Transmission Time
(seconds)0.854 0.420
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Experiment Scenario: Generation 3 Experiment
• Multi-threaded application with data-caching buffering
technique
• Monitor single vehicle for 40 minutes
• Wireless conditions: Good with one interruption
• Data resolution: 1 second
• Test Vehicle
• J1850 vehicle network
• CDMA2000/1xEV-DO wireless network
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Experiment Scenario: Generation 3 Experiment
Focus on this
time
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Experiment Scenario: Generation 2 Experiment 2
Timeouts
occurred
Send buffered data from
consecutive timeouts.
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Experiment Scenario: Generation 2 Experiment 2
Vehicle Test Vehicle
Total Data Strings Available 2488
Total Data Strings Gathered 2509
Transmission Attempts of Gathered Data Strings 2267
Timeouts During Transmission 48
Gathered Data Successfully Transmitted 2509
Percent Gathered Data Strings Buffered 42.85%
Percent Buffered Data Strings Successfully Transmitted 100%
Percent Data Strings Not Gathered -0.85%
Average successful transmission time (seconds) 0.433
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Conclusions: VPPTS prototype
• Developed a real-time vehicle performance monitoring
• Combined GPS and wireless networking technologies
• Incorporated vehicle performance data
• Integration of a GIS database
• Reduced initial resources
• Added greater interactivity (playback tool)
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Conclusions: Data Buffering technique
• Reduced data lost with wireless transmission compared
to a non-buffering system
• Retransmission of old data helps ensure data integrity
• Using a multi-threaded application enhanced this
technique
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Future Work and Research
• Delayed Transmission
• Accumulate multiple data strings at a time
• 5 – 10 second resolutions
• Buffering Technique Enhancement
• Monitor the network performance
• Dynamically change the send buffer
• Reduce the number of transmission timeouts
• GPS Signal as a Trigger
• Prevent duplicate data strings
• Produce more reliable performance analysis reports.
• Modular Architecture
• Seamless transition between wireless transmission mediums (cellular,
WIFI, WIMAX, etc.)
• Ad hoc vehicular network
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Questions
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References
• L. Figueiredo, I. Jesus, J.A.T. Machado, J.R. Ferreira, J.L. Martins de Carvalho, Towards the
Development of Intelligent Transportation Systems. IEEE Intelligent Transportation Systems
Proceedings, Oakland, CA, 2001, 25-29.
• Garmin. ―What is GPS.‖ [online]. Available: http://www.garmin.com/aboutGPS/index.html
• T. Yunck, G. Lindal, C. Liu, The role of GPS in precise Earth observation, Position Location and
Navigation Symposium, Dec. 1988, 251-258
• GSMWorld. [online]. Available: http://www.gsmworld.com/technology/faq.shtml
• J. Cai, D. Goodman, General Packet Radio in GSM, IEEE Communications Magazine, 35(10), 1997,
pp 122-131.
• S. Godavarty, S. Broyles and M. Parten, Interfacing to the On-board Diagnostic System,
Proceedings Vehicular Technology Conference Vol. 4, pp. 2000-2004, 24-28 Sept. 2000.
• SAE J 1850 May 2001, Class B Data Communication Network Interface, 2004 SAE Handbook, SAE
International, 2004.
• SAE J 1979 April 2002, E/E Diagnostic Test Modes Equivalent to ISO/DIS 15031: April 30, 2002,
2004 SAE Handbook, SAE International, 2004.
• NMEA 0183 Standard for Interfacing Marine Electronic Devices, Version 2.0, National Marine
Electronics Association, Mobile, AL, January 1992.
• J. Brittain, I.F. Darwin, Tomcat: the definitive guide (O'Reilly, 2003).
• K. English, L. Feaster, Community geography: GIS in action (ESRI Press, 2003).
• MARIS. [online]. Available: http://www.maris.state.ms.us/index.html
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In-Vehicle Networking (OBD-II)
• The 1990 Clean Air Act and the Environmental Protection
Agency established strict emission standards and
inspection/maintenance (I/M) programs.
• The Society for Automotive Engineers (SAE) produced a
set of automotive standards and practices that regulated
the development of diagnostic systems that would check
for emission violations.
• These standards were expanded to create the on-board
diagnostic system – OBD-II
• In 1996, the EPA adopted these standards and practices
and mandated their installation in all light-duty vehicles.
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Demo